I've just watched a video from the ninth 'The Amazing Meeting' - a popular skeptic meeting - wherein participants were asked to choose what they thought was the best argument for God.
I'd like to put in my two cents.
Argument from Universal Natural Selection
"Universe is as Universe does"
(This argument comes from my own shallow dive into cosmology, and represents the best argument I would make for God - I do most of my arguing on this subject in my own head, as I have yet to meet a religionist articulate enough to do it for me)
Though the originator of the universal natural selection theory, Lee Smolin, considers it falsified, it has become a darling of armchair cosmologists, myself included. It goes like this: each black hole gives rise to a new universe with different fundamental parameters (speed of light, planck length etc), and some of those universes are more "fertile" than others, i.e, are more able to give rise to further black holes. Some of those universes may even die a heat death before they can produce any offspring universes at all.
If each universe differs from its parent universe in some minor, random way, then you have the two forces you need for evolution - mutation and reproduction. This solves the goldilocks problem so often used by creationists - that the fundamental forces in our universe seem fine tuned to support life; we can just invoke the anthropic principle - we exist only in the universes where we are able to.
The Evolution of God
Solving problems posed by creationists will seem silly now that I am using this theory to argue for the existence of God. In any case, we're only one small step away from my point. If we accept that biological evolution can give rise to intelligence which can direct the course of further evolution, isn't it possible that universes would evolve to do the same, given enough time? If so, where could we see evidence for this? Maybe we're it.
Maybe it is the function of life to create black holes that are more finely tuned than the ones that occur by chance, thereby creating more fertile universes. Maybe it's something we'll choose to do, or something that will happen as a consequence of our nature (our lust for knowledge causes us to build ever larger supercomputers, one of which eventually collapses under its own gravity creating a more finely tuned offspring universe). If this has happened - if our universe was created by life forms in our parent universe - then they would be like gods to us. There's no predicting the forms they might take, or what abilities they might have to alter our reality.
Now, to be clear, I don't believe that this argument holds any water, it's just the best one I can come up with for the existence of a god. What do you think of the theory, and what's your best argument for God?